Digital life reporter Katie Humphrey covers all things Internet and culture, from apps and social media to goofy memes and studies proclaiming tech will doom/save us all. Chat with her on Twitter: @HumphreyKatie.

What are they worried about? Segmentation and balkanization of the Internet, evaporating trust amid government and corporate surveillance, commercial pressures squashing the flow of information and overreaction to oversharing that thwarts useful sharing.

David Weinberger, senior researcher at Harvard's Berkman Center for Internet and Society put it this way: "The future challenge: The Internet gets owned and packaged as a set of content and we treat it like cable TV. The future opportunity: Free culture becomes ever more lively, and people are enjoying content that they recognize was created by people like them."

Pew canvassed more than 1,400 experts to compile the report, the third in a series being released this year to mark the 25th anniversary of the Web's invention.

"While the majority of the survey respondents remain optimistic about the Internet's long-term future, they also have concerns about the turf wars emerging as these technologies mature," said Lee Rainie, director of the Pew Internet Project and co-author of the report. "Many experts worry that, if ignored, these problems could change the fundamental nature of this crucial information system."